Blind stitcher



July 21, 1953 H. N. JOHNSON 'BLIND STITCHER Filed Aprn 21, 1951 ATTORNEY Patented July 21, 1953 UNITED lSTATES PATENT OFFICE BLIND SITITCHER Harry N. Johnson, New Haven, Conn., assignor to The Greist Manufacturing Company, New Haven, Conn., a corporation of Connecticut Application April 21, 1951, seria1No.22z,19v

l 9 Claims.

This invention relates to an attachment for sewing machines and more particularly to an attachment for effecting a so-called blind stitch, which attachment may be applied to the `ordinary sewing machine designed for household use.

It is desirable that a household sewing machine be equipped for accomplishing many kinds of work in addition to plain sewing, and in connection with the hemming of a piece of cloth, it is desirable to provide an attachment for effecting a so-called blind stitch in sewing the hem. This is accomplished in the present construction by providing an attachment which` willproduce a number of stitches in a straight line and at regular intervals effect an offset stitch or a stitch spaced from the line of stitching referred to.

The attachment is provided with a cloth-holding foot pivotally attached to a frame adapted to be secured to the presser bar of the sewing machine, and provision is made for shifting this foot pivotally at regular intervals in the operation of the machine to move the cloth laterally to effect an offset stitch. The cloth is then shifted back to its original position so as to continue stitching in a straight line until the lateral shift is again made to produce another offset stitch, it being understood that the offset stitch is produced at space intervals along the line of sewing.

Moreover, by the present construction there is provided a device of simple character which may be economically manufactured, which consists of a relatively small number of parts.

One object of the invention is Yto provide a i new and improved blind stitch attachment for household sewing machines.

A further object of the invention is to provide a blind stitch attachment for sewing machines which will be relatively simple in construction and which will be provided with relatively few movable parts subject to wear.

Still another object of the invention is to provide a blind stitch attachment for sewing machines comprising elements which may be readily and accurately manufactured by stamping operations and assembled into a complete device which will operate in a certain manner.

To these and other ends the invention consists in the novel features and combinations ofl parts to be hereinafter described and claimed.

In the accompanying drawing:

Fig. 1 is a side elevational view of a sewing machine attachment embodying my invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a sectional view of the device on line 3-3 0f Fig. 2;

` my invention;

wheel 24.

Fig. 'l is a sectional view on line 'I-'I of Fig. 6; and Y Fig. 8 is an exploded View of certain of the parts of the attachments shown in Figs. 6 and 7.

To illustrate a preferred embodiment of my invention I have shown in Figs. l to 5 of the drawing a blind stitch attachment comprising a frame adapted to be secured to the presser bar of a sewing machine. As .shown more especially in Fig. 4, this frame comprises a base plate IQ and an upstanding Wall or flange II upon one side, and a small upstanding, substantially parallel ange I2 at the other side, these parts being formed integrally with each other.

A lever I3 is pivotally attached to the base III, the lever being provided with a downwardly offset portion III, and a further downwardly oiTset end portion forming the cloth-holding foot I5. The portion I4 of this lever is provided with an opening I6 which receives a pivot pin Il secured to the base II) of the frame so that the lever I3 rocks about the pin I1 as a pivot.

Upon the body portion of the lever is an up standing pin I8 which extends through a laterally elongated slot I9 in the base I, and at its rear end a guide pin 2D is secured to the lever I3, which pin is received in a laterally elongated slot 2l at the rear of the base, which pin and slot limit the lateral movement of the lever and at the same time hold it in contact with the base as the pin is provided with a head 22 which contacts the upper surface of the base I0 at the edges of the slot 2|.

Rotatably mounted in the flange member II is a short shaft 23, to one end of which is secured a ratchet wheel 2li, this wheel being rotated in a step-by-step manner by the oscillation of the usual fork arm 25, which is pivoted on the shaft 23. A pawl 26 is pivoted at 2l on the fork arm and engages the teeth of the ratchet A spring 2,8 is carried bythe fork arm and one end of vthis spring, as shown at 29, extends through an opening 30 in the fork arm to engage the pawl 26 and urge it into engagement with the teeth of the ratchet wheel.

Upon the side of the frame member II opposite that on which the ratchet Wheel 24 is disposed, a cam member 3| is secured to the shaft 23 which, as shown, is provided with a pair of cam ngers 32 projecting outwardly at substantially diametrically opposite positions.

An actuating slide member 33 (Figs. 3' and 4) is slidably mounted upon the upper surface of the base I0, this member being held in position by the pin 33a and by a pin 34 which is secured at its ends in the flanges I I and I2 and lies above the plate 33 so .that it is held slidably'rupon the base member. This actuating slide 33 is provided with a cam-shaped slot 35 which receives the end of the pin I8, which projects above the base I0, and it will be obvious that as the slide member is moved to and fro in a longitudinal direction upon the base I0, the cam slot 35 will effect lateral movements of the pin I8 and, therefore, eiect lateral swinging movement of the lever I3 about its pivot II. This in turn effects lateral movements of the cloth-holding' foot I5 to move the cloth to one side of the normal line of stitching.

Movement of the slide 33 in a forward direction is effected by means of the cam lingers 32 which are designed to engage one arm 35 of an L-shaped iiange formed integrally with the slide member 35 and upstanding therefrom. Movement of the slide in a rearward direction, or to the left, as shown in Fig. 3, is effected by a tension spring 3l secured at one end to an arm 38 formed integrally with the flange II, and at its other end to the other arm 39 of the` L-shaped flange on the slide 33.

The base member I may be provided at its forward end with a slot 4I) by which it may be attached to` the presser bar of the sewing machine. Reverse movement of the ratchet wheel 24 may be prevented by a holding detent 4I so that upon reciprocation of the fork arm, the ratchet wheel will be moved in one direction only.

From the above it Will be obvious that as the needle bar reciprocates, the fork arm 25 will be oscillated about the shaft 23 in a vertical plane. Through the engagement of the pawl 25 with the teeth of the ratchet wheel 24, the shaft 23 will be rotated in a stepbystep manner, and this will serve to rotate the cam 3|. When one of the cam lingers 32 engages the iiange 36 on the slide, the latter will be moved forwardly, as shown in Fig. 5. Movement of the slide forwardly will, due to the shape of the cam slot 35, move the lever I3 about its pivot I'I, and, therefore, effect lateral movement of the clothholding foot I5.

When the cam finger 32 rides out of engagement with the member 35 upon a continued rotation of the cam 3I, the spring 31 will move the slide 33 rearwardly and return the foot I5 to its original or normal position. This normal position of the slide is shown in Fig. 3, which is the position occupied by it just prior to its being moved forwardly by one of the lingers 32. As shown, there are twelve teeth on the ratchet wheel 24, and it will be seen, therefore, that there will be five plain or straight line stitches between two adjacent offset stitches made by the lateral movement of the lever I3. obvious that the attachment will produce live stitches in a straight line and upon the next upward movement of the fork arm 25 the cam linger 32 will move the slide 33 forwardly and move the cloth laterally by swinging the lever I3 about its pivot. The needle will then descend to make the offset stitch at which time the cam 3| will be stationary. Upon the next upward movement of the needle bar and fork arm 25, the cam linger 32 will ride out of engagement with the flange V36, .and .the slide `member will be It Will be 4 returned to its original position, thus returning the foot I5 to its normal or original position for straight line sewing, after which another live straight line stitches will be effected, and then a second offset stitch.

It will, of course be obvious that the number of straight line stitches effected by the two adjacent offset stitches will be determined by the number of cam lingers 32 which are provided, and by the number of teeth in the ratchet wheel 24.

In Figs. 6 to 8 of the drawing, I have shown a slightly modified form of my invention. In this instance the frame portion of the device consists as shown in Fig. 8 of a base portion 35 and upstanding parallel flanges I6 and Lil. To the base portion 45 is connected the lever I 321 which carries the cloth-holding foot I5a, which are substantially like the corresponding elements described in connection with the modification shown in Figs. 1 to 5, and the lever is connected to the base in the same manner for rocking movements about the pin Ila. It is also provided with the pin I8a which extends upwardly through the slot I9a in the base member (I5.

A substantially U-shaped slide 48 is slidably attached on the upper surface of the base l5 and held in place by the pin 49. The member i3 is provided with the cam-shaped slot 59 which receives the pin IBa and which upon reciprocation of the slide will effect oscillation of the lever I3a about the pivot pin I le.

A hub member 5I is rotatably mounted in openings 52 and 53 of the upstanding flanges l5 and 41, and this hub member is rotated in a step-by-step manner by the fork arm 55., as shown in Fig. l. Secured in the hub member 5I substantially midway between the iianges l5 and Il is a pin 55, both ends of which project from the hub member, as shown in Fig. '7.

The ends of the pin 55 are adapted to engage an upstanding lug 56 secured to the slide 1138, and upon rotation of the hub member 5I, the engagement of the ends of the pin 55 with this hub member will eiiect forward movement of the slide. When the ends of the pin 55 upon continued rotation of the hub member ride out of engagement with the lug 55, the slide is returned to its rear or normal position by a tension spring 5l secured at one end to the pin 58 and at the other end to an ear 59 on the slide.

The operation of the device shown in Figs. 6 to 8 is substantially like that shown in Figs. l to 5. Upon reciprocation of the needle bar of the sewing machine the hub 5I will be rotated in a step-by-step manner. The normal position of the parts is that shown in Figs. 6 and. 7 wherein straight stitching is effected. When the hub reaches the position shown in Fig. '7, the lower end of the pin 55 will engage the lug 55 and move the slide forwardly, whereupon the engagement of the cam slot 50 with the pin I 8H will effect lateral movement of the lever I3a and the cloth holding foot I5*I to effect an offset stitch. Upon the next upward movement of the fork arm, the end of the pin 55 will ride out of engagement with the lug 56 and permit the spring 5i to return the slide and the lever |32* to its original position.

While I have shown and described some preferred embodiments of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modiiication and variation within the spirit of the invention and within the scope of the claims.

What I claim is: y

1. In a blind stitch attachment for sewing machines, a frame having a horizontally disposed base member, a lever pivotally secured to the base member, said lever being provided with a cloth-holding foot at its forward end, a slide movably mounted on the base member and provided with a cam slot, said lever having a part engaged in said slot, an oscillatable fork arm mounted on the frame, means actuated by the fork arm to move said slide in one direction and a spring connected to the frame member and slide to effect return movement of the slide.

2. In a blind stitch attachment for sewing machines, a frame having a horizontally disposed base member, a lever pivotally secured to the base member, said lever being provided with a cloth-holding foot at its forward end, a slide movably mounted on the base member and provided with a cam slot, said lever having a part engaged in said slot, an oscillatable fork arm mounted on the frame, means actuated by the fork arm to move said slide in one direction and a spring connected to the frame member and base member, a lever pivotally secured to the base member, said lever being provided with a cloth-holding foot at its forward end, a horizontally disposed slide movably mounted on the base member and provided with a cam slot, said lever having a part engaged in said slot, said slide having an upstanding member thereon, and means engaging said upstanding member for moving said slide to effect movement of the lever about its pivot, said means comprising a cam member rotatably mounted on the frame and having a finger adapted to engage a part of the slide.

4. In a blind stitch attachment for sewing machines, a frame having a horizontally disposed base member, a lever pivotally secured to the base member, said lever being provided with a cloth-holding foot vat its forward end, a slide movably mounted on the base member and provided with a cam slot, said lever having a part engaged in said slot, means for moving said slide in one direction comprising a cam member rochines, a frame having a horizontally disposed base member, a lever pivotally secured to the base member, said lever being provided with a cloth-holding foot at its forward end, a horizontally disposed slide movably mounted on the base member and provided with a cam slot, said lever having a part engaged in said slot, said slide having an upstanding member thereon, a fork arm pivotally carried by the frame, a member rotatably mounted on the frame and having a projecting element thereon adapted to engage the upstanding member on the slide to move the latter longitudinally of the base member to effect lateral movement of the lever about its pivot, and means for effecting rotation of said member by oscillation of the fork arm.

7. In ablind stitch attachment for sewing machines, a frame having a horizontally disposed base member, a lever pivotally secured to the base member, said lever being provided with a cloth-holding foot at its forward end, a slide movably mounted on the base member and provided with a cam slot, saidlever having a part tatably mounted on the base and having a finger adapted to engage a part on the slide, and a spring connected to the frame member and slide to move the slide in the opposite direction.

5. In a blind stitch attachment for sewing machines, a frame having a horizontally disposed base member, a lever pivotally secured to the base member, said lever being provided with a cloth-holding foot at its forward end, a horizontally disposed slide movably mounted on the base member and provided with a cam slot, said lever having a part engaged in said slot, said slide having an upstanding member thereon, and means engaging said upstanding member for moving said slide to effect movement of the lever about its pivot, said means comprising a cam member rotatably mounted on the frame and having a finger adapted to engage a part of the slide, a fork arm pivotally carried by the frame, means connecting said fork arm to the cam member to eiect step-by-step movement of the cam member upon oscillation of the fork arm.

6. In a blind stitch attachment for sewing maengaged in said slot, a fork arm pivotally carried by the frame, a member rotatably mounted on the frame and having a projecting element thereon adapted to engage a part of the slide to move the latter longitudinally of the base member in one direction and a spring connected to the frame member and slide to move said slide in the other direction and means to efect rotation of said rotatable member by oscillation of the fork` arm.

8. In a blind stitch attachment for sewing machines, a frame having a horizontally disposed base member, a lever pivotally secured to the base member, said lever being provided with a cloth-holding rfoot at its forward end, a horizontally disposed slide movably mounted on the base member and provided with a cam slot, said lever having a part engaged in said slot, said slide having an upstanding member thereon, a fork arm pivotally carried by the frame, a hub member rotatably mounted on the frame and having a pin projecting therefrom and adapted to engage the upstanding member on the slide to move the latter longitudinally of the base member and eiect lateral movement of the lever about its pivot, and means for effecting rotation of said hub member by oscillation of the fork arm.

9. A blind stitch attachment for sewing machines comprising a frame having a horizontally disposed base member, a levervpivotally secured to the base member at the under side thereof, said base member provided with a transverse elongated slot and said lever being provided with a pin projecting upwardly through said slot, a slide member movably mounted on the upper face of'said base member, said slide member being provided with a cam-shaped slot to engage said pin, an element rotatably mounted upon the 'frame having a part to engage said slide to move the latter in one direction, a forli arm pivotally mounted on the frame and connected to said rotatable element to rotate the same, and a spring connected to said slide and frame to move the slide in the opposite direction.

HARRY N. JOHNSON.

Country Date Germany Dec. 21, 1934 Number 

